Tuesday, May 6, 2014

Deconstructing the "don't bike with a helmet" crowd

It seems like something that occurs every few months. Someone doesn't like wearing bike helmets, and rather than ride around without a helmet on, they decide that everyone would bike more if it wasn't for those pesky helmets, and they decide to write about it on the Internet. They find some studies, draw some conclusions, and use data to say "hey, look, it's actually safer to bike without a helmet." Here's the thing:

THEY ARE WRONG.

The latest installment comes from Howie Chong. I'm sure Howie is a heck of a guy. But before he tells people not to wear helmets, he should get his facts straighter. Here's his thesis:

I have made a careful and conscientious choice to not wear a helmet when I’m cycling in urban areas because I strongly believe that it will help improve the overall safety of cycling in the long run.

And here's what I have to say about it …

Let’s first get one thing out of the way: if you get into a serious accident, wearing a helmet will probably save your life. According to a 1989 study in the New England Journal of Medicine, riders with helmets had an 85% reduction in their risk of head injury and an 88% reduction in their risk of brain injury. That’s an overwhelming number that’s backed up study after study. Nearly every study of hospital admission rates, helmeted cyclists are far less likely to receive serious head and brain injuries.

If the piece he wrote ended here, it would be fine. Studies do back this up. If you are in a crash, a helmet will dramatically improve outcomes. Now, he's going to spend a few dozen paragraphs circling around this with some very loose logic attempting to negate all of these benefits. He describes auto traffic and goes on:

So a helmet provides a level of protection from this danger. It makes you feel safer.

No! A helmet does not make you feel safer. This is false equivalence. On the one side, we have data showing that a helmet makes you safer. As he points out in his first paragraph, a helmet makes you safer. On the other side, we have a perception of how a bicycle rider feels (he extrapolates this to all riders). It it not touchy-feely. Helmets reduce the risk of head injury seven-fold. That's not a feeling.

But a broader look at the statistics show that cyclists’ fear of head trauma is irrational if we compare it to some other risks.

He goes on to cite a 1978 study from San Diego that attributes 6% of head injuries to bicycling and 53% to automobiles.

The studies that are out there give us mixed messages about the relative safety of the different modes of transport. What I am saying is that these statistics raise an interesting question: If we're so concerned about head injuries, why don't we wear helmets all the time? Why do places that have mandatory helmet laws for cyclists not have them for drivers or pedestrians?

No, they don't give us mixed messages. They just don't give us enough data. I don't have the numbers from 1978, but more recently (from 1990 to today; there has been little bicycling growth in San Diego), about 1% of San Diegans biked to work. 85% drove. Once you control for these denominators, the numbers change dramatically. Bicyclists account for 600% more head injuries than would be expected based on their mode share, cars account for 60% fewer. Drivers have seat belts designed to keep their heads away from hard objects. Pedestrians are usually on sidewalks and only interact with vehicles in intersections. Bicyclists, on the other hand, have none of these protections.

He goes on to describe a Forbes article which suggests that graduated licenses are the best way to reduce head injuries among teenager short of forcing them to wear helmets, a comment made surely in jest. His response:

Despite the fact that car accidents are the number one cause of all fatal head trauma among teenagers, the suggestion that teens wear helmets when they drive is simply brushed off. The passage treats the idea of mandatory driving helmets as completely preposterous.

Again: No! The idea of wearing helmets is preposterous because helmets would not help in a car accident. There are certainly no studies. What keeps you safe in car accidents are seat belts and headrests. If you are properly bucked in to a car and are in an accident, your risk of head injury is dramatically reduced because your head is kept away from metal and pavement. This is what headrests and seat belts and roll cages are designed to do. A helmet would just sit there flopping around. He asks "Why has cycling been singled out as an activity in need of head protection?" Because we've already addressed passive protection in cars.

He doubles down:

Bike helmets may reduce the risk of head and brain injury by 85-88%—but only for those who get into accidents.

Oh, good, I'll just never get hit by cars. Good.

If we take a closer look at the article we see that both the experiment and the control groups studied are those who have already been hospitalized for bike injuries. … Studies show that helmeted cyclists who are hospitalized are far less likely to have serious head trauma than bare-headed cyclists that have been hospitalized. But wouldn't this be true, regardless of the activity? Logically, helmeted drivers should also receive significantly fewer head injuries than bare-headed drivers. Similarly, helmeted pedestrians should be less likely to receive serious head trauma than bare-headed ones.

But such studies don't exist because there aren't enough helmeted drivers or pedestrians to make a comparison. In other words, one of the reasons we think helmeted cyclists are safer than unhelmeted ones may be due to availability of information more than actual levels of head safety.

Maybe that explains why there's no comparable fear of driving or walking without a helmet.

My head is spinning. Where to begin. How about "Logically, helmeted drivers [are safer]." This is illogical. Again, drivers in cars are protected by different mechanisms which achieve similar results. Seat belt use dramatically reduces the severity of head injuries. Think of the seat belt as the helmet of a car. It's the first line of defense. It serves the same purpose. And there are plenty of studies that show this. There is no information deficit. Comparing helmet use among drivers and cyclists is comparing apples to oranges. Helmet use to seat belt use is the right comparison here.

He goes on to cite a New York Times article from 2001 regarding helmet use. It, however, does not draw any conclusions, and several of the anecdotes it gives pertain to mountain biking, not the kind of bicycle commuting which has grown dramatically in the past 15 years. It doesn't conclude that more helmets correlate with higher head injury rates. If it comes to any conclusion, it's that helmet use is just a part of bicycle safety.

Then he goes on about a study which shows that drivers will give more space to an unhelmeted cyclist than a helmeted one. Fine. How about education and enforcement for cars which squeeze bicyclists, whether they're wearing a helmet or not.

The he gets in to mandatory helmet laws.

So as much as helmets decrease the chance of head injury when you get into an accident, they may actually increase your chance of getting into an injury in the first place.

Again, this is a very much false equivalence. On the one hand, helmets make you safer, and there's data to back that up. On the other hand, they may increase your chance of being in an accident, but no one knows. They may not.

There is another significant way that the use of helmets harm cyclists: Bike helmets discourage cycling. An Australian study on mandatory helmet laws concluded that laws that required cyclists to wear head protection actually decreased the number of cyclists on the road. The implication of this study? The fewer cyclists on the road, the less likely drivers will be accustomed to sharing road space with cyclists, ultimately increasing the hazards faced by cyclists and further dissuading people from hopping on their bikes.

First of all, this is regarding a mandatory helmet law. I lived in Melbourne and people were not happy about that law. But a helmet law is very different than suggesting that people wear a helmet. In the US, at least, if people don't wear a helmet they don't have to worry about being given a $100 ticket. That is much of what discourages cycling where helmets are mandatory. I agree that helmet laws are heavy-handed and bad policy (for bicyclists, anyway; they are certainly a good idea for motorcyclists).

[O]ur society has conditioned cyclists to feel unsafe without a helmet, even though wearing one might actually increase the chance of a collision with a vehicle; and even though other activities capable of inflicting serious head wounds are enjoyed bare-headed without stigma.

Again with the false equivalence. We feel unsafe without a helmet because it is statistically less safe to bike without a helmet. There is no data that shows that cyclists without helmets get in to fewer accidents.

Helmet use is very uncommon in bike-friendly cities like Copenhagen and Amsterdam, where cyclists have been socialized to see cycling as a safe activity. In order to promote the same culture here, we need to encourage people who don't bike that they should give it a try.

What else do they have in Amsterdam and Copenhagen? They have protected bicycle infrastructure. They have laws which assign blame and real, actual legal remedies to drivers involved in bike-car collisions. Nearly everyone is, at some point, a cyclist, so they know to look for other cyclists, even when they're driving. The assertion that if we don't wear helmets we'll suddenly turn in to Copenhagen is ridiculous.

If there was conclusive proof that bike helmets reduce the total number of serious head injuries compared to other normal activities, then I'd reconsider my stance.

There is conclusive proof! This "other normal activities" (driving and walking) is a total red herring; we don't wear helmets when driving because we have other protections in place, and we don't walk in mixed traffic on the highway. This statement is completely illogical.

But if I'm not the kind of person who wears a helmet when I take a walk or get behind the wheel of a car, then there's no logic to me wearing one when I'm on a bike, particularly if I'm confident in my urban bike safety ability.

Do you put on a seat belt when you get in a car? If so, you are the kind of person who wears a helmet when you get behind the wheel of a car. (I'll get to the confidence in urban bike safety in a moment.)

Meanwhile the proof is pretty strong that vehicles give me more space when I'm biking without a helmet.

Okay. So you dismiss the proof that wearing a helmet makes you safer. But when it comes to a single study that shows that unhelmeted cyclists, it holds a lot of water. The study also showed female cyclists got more room. Maybe Mr. Chong should consider a sex change, or at least a wig.

In a city biking, that's the kind of injury I'm most concerned about.

Now, let's go in to personal anecdotes. About two years ago, I was biking to work. 2.5 miles, mostly in bike lanes, and on a route I knew very, very well. It's the exact type of situation that Mr. Chong would eschew a helmet:

I was on a street with a bike lane

It was sunny and warm

I was biking in the only League of American Bicyclists Gold-rated city on the East Coast

I was in a city with a 9% bicycle mode share; the fifth highest in the country, so cars should be used to looking for cyclists

I was following all traffic rules

None of this precluded a driver parked across the street blindly making a U-turn in to my path. I barely had time to brake and hit his car at full speed. I was scraped up and had a minor concussion and some residual back pain for a couple of months. I also had a helmet with a visible crack in it. Had I not had this helmet, the crack would have likely been to my head.

If I hadn't been wearing a helmet, the driver still wouldn't have seen me. He didn't look down the road and see me and say "oh, a helmeted cyclists, I am now going to make an illegal U-turn." He didn't look at all. Not wearing a helmet would have potentially turned me in to a vegetable, and that is certainly not a way to get people to bike in the long run. ("Oh, I'm not riding a bike; Ari was biking to work and some moron turned in to him and now he eats through a tube" is not a good way to encourage bike riding.) We have a long, long way to go before bicycling in America looks anything like Copenhagen or Amsterdam; we'd have to reform infrastructure, law and behavior dramatically. Until then, it most certainly makes sense to wear a bike helmet when riding a bike.

25 comments:

I feel like I read a different article from you. I got something different out of it, which is, "if you have a helmet, wear it. If you don't have a helmet, don't stress about it too much."

quote:``I'm not saying that adults should not wear bike helmets. The main point I'm trying to make is that, when compared to other forms of transportation, the fear of head trauma from cycling is likely out of proportion to the actual risk — and that fear is leading many advocates to admonish bare-headed cycling and contribute to a culture that's counter-productive to the overall safety of all cyclists.''

Also, from an Australian paper he cites later, quote:``Despite the risk of dying from head injury per hour being similar for unhelmeted cyclists and motor vehicle occupants, cyclists alone have been required to wear head protection.''

http://www.sciencedirect.com/science/article/pii/0001457596000164

Being a casual Hubway user means that I don't know if I am going to use a bike that day when I leave the house. If I do intend to ride a bike when I leave the house then I bring my helmet. Most days I will not use a bike. But if something comes up when I am far from the house, and Hubway is the most convenient way to get where I am going, then I will use Hubway without going back home to fetch my helmet. I believe the expected value of riding Hubway, both in health and time, outweighs the additional risk.

You're making the same mistake that Chong does: a helmet on a bike is not a helmet in a car. If we didn't have headrests and seat belts in cars, we'd see much higher head injury rates for vehicles. Wearing a helmet is akin to buckling a seat belt.

No, the article had a high level of holier-than-thou to it. He's justifying not wearing a helmet not by saying "I don't want to" but "I'm making bicycling safer for everyone." It's disingenuous, and it's wrong. Encouraging helmet use is not counter-productive to safe cycling, it's an important part of it. And I don't think you read my argument that saying that drivers should wear helmets is the definition of a false equivalence.

I'm not saying that people should or should not wear helmets. I'm saying that these sorts of arguments are based on feelings, not facts.

My frustration on the original article was with his data. As you mention in his report from 1978 " that attributes 6% of head injuries to bicycling and 53% to automobiles." It also fails to mention that this was 1978, and California Seat Belt laws didn't come into effect until January 1st, 1986! 8 years later.

The argument that he doesn't wear a helmet in the car falls flat as soon as he realizes "I can't wear a seat belt on my bike" or "my bike doesn't come with air-bags standard". He clearly points out "an 85% reduction in their risk of head injury and an 88% reduction in their risk of brain injury." But the completely ignores that by stating: "If there was conclusive proof that bike helmets reduce the total number of serious head injuries compared to other normal activities, then I'd reconsider my stance."

Your life and safety at risk, you shouldn't compare it to 'other normal activities' You should compare it to "Riding with one as opposed to riding without one" And again, don't compare to other 'normal activities' before taking into account things like the other safety measures they already have.

I crashed after a seizure while biking - I landed on my chin. I suffered a Traumatic Brain Injury...and I still don't wear a helmet.

" On the one side, we have data showing that a helmet makes you safer."

That data is more than suspect. A thorough review of the research shows no evidence that cycling with a helmet is safer than biking without one. This is likely due to 1) flimsy POS piece of styrofoam design of bike helmets and 2) many ways bike helmets decrease safety.

So why use an inferior piece of safety gear that is nothing but a pathetic counterfeit version of a real helmet?

"Think of the seat belt as the helmet of a car. It does the same thing."

Nonsense. Seat belts prevent one from hitting ones head. Helmets insulate the head AFTER one hits ones head. This statement is saying condoms and abortions perform the same function.

If I start wearing a helmet I suppose I should strap on a piece of cardboard over my torso, as a bulletproof vest...and looking into reusing other bits of recyclable trash as pseudo-safety gear.

"A thorough review of the research shows no evidence that cycling with a helmet is safer than biking without one."

No.

"The many ways helmets decrease safety."

There aren't ways that helmets decrease safety. This is a red herring. Helmets don't make you completely safe: as you pointed out, you can land on your chin and concuss yourself (I did this once slipping on a patch of ice). But the data are clear: helmets make you safer; the data that wearing a helmet somehow makes you less safe are muddled at best.

"That data is more than suspect. A thorough review of the research shows no evidence . . ."Anyone who thinks this statement MIGHT have validity should read some of the Harry Hurt report(s). (USC. His work and studies continued after the publication of the initial report in 1981).

" . . . that cycling with a helmet is safer than biking without one. This is likely due to 1) flimsy POS piece of styrofoam design of bike helmets and 2) many ways bike helmets decrease safety. . . ."Wow. All I can say is check out http://www.informationisbeautiful.net/visualizations/rhetological-fallacies/ and see how many times you can get this statement to match the conditions listed.

As for claims that the helmets today lack protection, that they are too lightweight or otherwise ineffective? Wait a sec - how did we get from "helmets decrease safety", to "helmets don't do anything"? For those who seriously think that helmets today offer little or no protection - look at the market BEFORE the ANSI standard back in 1980-something. At LEAST the ANSI standard provide SOMETHING to standardize design. It may not be perfect - but it is better by a few country miles than no standard.

I wear a bike helmet because I recognize it will likely make me marginally safer and it is part of the social norm. I don't wear a helmet driving because it will likely make me marginally safer and isn't part of the social norm. If it was, I probably would. With that said, I found the article in question to be a very interesting read, and I think someone should be bringing up his points. While it doesn't take away my ability to make my own choice on the matter, I appreciate the interesting perspective. I agree with this author that there needs to be some serious consideration before nixing bike helmets altogether, but that (increased consideration and research of the topic) is also part of the original authors goal.

I do, however, believe the original article raises enough points that a productive conversation would be in order. While I feel the above article is an attempt at that conversation, it reads more like someone, having done no research, yelling at his computer screen while he reads (and ignores many parts of) the original article.

As a side note, while cars do have more than one safety feature, that's no reason to not wear a helmet in one. An additional safety feature is never a bad thing if the problem (vehicle brain injuries) is still prevalent.

The margins of safety are vastly different. Orders of magnitude. There are safety measures in place for your head when you are in a car crash that dramatically reduce head injuries. 1) you are belted in to your seat, so you don't go crashing through the glass. 2) your seat is attached to the vehicle body, so the seat doesn't eject through the roof. 3) There is a headrest to keep your head from snapping backwards. These all dramatically improve safety. The helmet would add a margin on top of that, but the margin has already been decreased by these improvements.

On a bike, there is no protection for your head. A helmet is your first line of defense, not your fifth. It's a big difference.

No, on a bike the fact that you're more likely traveling at "stumbling speed" rather than "death speed" is your first line of defense. You can't fairly compare the safety measures of being in a car vs. on a bike in 1:1 fashion when the top 25 reasons people suffer serious injuries in these accidents basically come down to speed at point of impact.

That may be difficult for the Lycra-clad road warrior set to relate to so let me try this: the point of all this "no helmet" mumbo jumbo is to say "hey folks, slow down, chill out, this is supposed to be easy and convenient, not an extreme sport with multiple equipment barriers to entry."

If you're on a bike and get hit by a car, the speed you are traveling is irrelevant. If you are thrown in the air and fall to the ground, simple gravity will mean that you are moving at a pretty good clip. If your head ricochets through the air and in to the pavement, it's going plenty fast enough to do serious damage, and for a helmet to help. If you putter along a bike path at 8 mph, fine, don't wear a helmet. But even then, if you fall to the ground, you can concuss yourself pretty well just from the five feet it takes your head to go from head-level to asphalt.

As an addendum to my above comment, I am trying to say that it isn't a bad thing to do more research on the topic. I don't have to buy into the assertion that helmets make you less safe (an assertion I find unlikely to be true) to want to know the actual risk involved in not wearing a bike helmet.

If it was found that it presented less of a risk than, for example, not wearing a helmet when walking down the street, then I would not only want this information before I support certain laws, judge others for not wearing a helmet, or drop $50 on a top-of-the-line helmet, but also before I walk to class without a helmet.

It is likely that in the case of comparable risk of brain injury from biking and walking I would eventually stop wearing a helmet on my bike, but, in that case, I would be making a logical decision based on my own weighting or pros and cons. I think the author of the original article is trying to say that there is a certain degree of risk that people generally accept and go on about their lives with, and wearing a helmet while biking may be an outlier. If true, that would make some people not want to wear a helmet while engaging in that activity, and others want to wear a helmet more of the time. Both of those results should be ok and not steeped in prejudice.

I think you might have a good argument buried in here, but I find it impossible to read past your logic blunder and histrionics.

1. You say "If you are in a crash, a helmet will dramatically improve outcomes.", suggest that he should have stopped there.

It would be more correct to say, "If you are in an accident that requires hospital admission, a helmet will dramatically improve outcomes". In fact, you may as well say, "If your head is struck, a helmet will reduce the damage", which is basically a tautology.

The point is, these are all useless information, unless your only goal is to reduce head injury. If you have a broader goal, like "reducing overall injury", the statement you highlight is not enough information to decide.

2. You bafflingly insist, "No! A helmet does not make you feel safer. This is false equivalence. On the one side, we have data showing that a helmet makes you safer. As he points out in his first paragraph, a helmet *makes* you safer".

WTF? Are the two mutually exclusive? Typically, when people consciously adopt safety measures, they also *feel* safer. Typically, the correlated *feeling* of safety leads to compensatory risk, which is obviously why the author brings it up.

3. "What keeps you safe in car accidents are seat belts and headrests"

WTF? Are these mutually exclusive versus helmets now? You acknowledge that major head trauma in a car is equally common as on bicycles, but then somehow claim it's impossible to have major head trauma in a car. You're incoherent.

Are you seriously claiming that all of the head injuries that happen in cars would be unhelped by helmets, because "a helmet would be flapping around"?

4. You say, "This "other normal activities" (driving and walking) is a total red herring; we don't wear helmets when driving because we have other protections in place, and we don't walk in mixed traffic on the highway."

OK, we've already seen that "those other protections" don't reduce the rate of head trauma in automobiles, and every study of head trauma has shown that helmets reduce the damage. If you're going to argue that cars somehow render helmets ineffective, you would need to back that up with data.

But your point about walking is the most baffling. Yes, people don't walk on highways. Yet they sustain high rates of head trauma when walking. I can't tell what you're saying. Are you arguing that their head trauma is unavoidable, since they already abstained from walking on the highway? Or are you saying that they deserve it, because obviously they wouldn't get the head trauma unless they did something wrong? And are you saying that helmets would *not* reduce the damage of head trauma? Again, the burden is on you to show that helmets are strangely ineffective for pedestrians.

And it's flatly false to say that walking and driving are irrelevant. The author makes two very mild arguments, which you so far have failed to refute:A) *If* you are worried about overall safety when riding a bike, there is no evidence that helmets helpB) *if* you are instead worried only about reducing injury in the event of head trauma, you should be at least as worried about head trauma when walking or driving.

If, on the other hand, you are *only* worried about head trauma when riding a bicycle (perhaps because a personal incident anchored you to hyper-focus on this singular risk), then by all means, wearing a helmet is the right thing to do.

5. An anecdote.

Your only legitimate argument is an anecdote, and it certainly explains why you are so irrational about this issue. I'm sorry that happened to you.

1. Any time you hit your helmet instead of your head, you will dramatically improve outcomes. Here are four anecdotal examples (I'm not trying to say that these are data, but things that have happened to me):

* Biking in to high school, a car stopped short in front of me. My back wheel hit the car, my helmet hit the windshield. I was fine. The helmet had a dent in it instead of my head. No hospital, much less of a concussion. * Mountain biking in Maine, I hit a rut and my head went in to a tree. Again, no hospital, dent in helmet. * Biking in Allston, Mass I hit a pothole. 8" deep. Endo-ed. I fell mostly on my pack and iPhone, but also hit my head pretty well. I was fine, my helmet was replaced. * The story in this post.

In all of these situations, the helmet I was wearing reduced the level of injury over not wearing a helmet. I can not think of any situations where wearing a helmet has increased injury.

2. What I am pointing out is that if you cite a study that says, in a nutshell, "a helmet makes you safer" you should just say "helmets make you safer" and not couch it as being a feeling. Certainly helmets may make people feel safer. But that's because they are safer. It seems weasel-y to say that a helmet only makes you feel safer.

3. First of all, I'm not saying that major head trauma is equally common in cars than on bicycles. If you accept the 1978 study the original author cites, head trauma is significantly more common for cyclists. Regarding "a helmet flapping around" my point that I made in a previous comment response is that in a car a helmet would be your third or fifth line of defense, on a bike it's your first. If we didn't have seat belts, air bags and headrests, yeah, I might wear a helmet driving.

4. Wait, since when do seat belts and head rests not reduce head trauma. Google "seat belts and head injury" and you'll find this which says that seat belts do reduce head injuries. I feel like I am repeating myself because I linked to that article above. So be it.

I don't want to get this way off topic, but if you're walking, generally you need a relatively drastic force to knock you in to the ground with enough force to cause a head injury. If you're bicycling, you are going faster and are less stable. So a helmet is more likely to come in to play. (I've walked—a lot—in my life, and had one concussion falling on ice. I've biked a lot and had four times a helmet helped me out.)

Re the author's comments: If you are worried about overall safety when riding a bike, part of overall safety is head injuries. Helmets help there. If you are worried about head injuries when walking or driving, helmets are likely not as effective as when bicycling. There are no studies of the effects of helmets on walking and driving, but that's not a reason not to wear them cycling.

5. It is rational to wear a helmet, and make the points I've been making. It has also saved my tail a few times, as well as many of my friends.

You say helmets saved you a few times, but you left out some important details, such as your speed. Higher speeds reduce reaction time. Also, there's the physics of speed. At slower speeds, if you crash, you're more likely to go down with the bike. Anecdotally, this has happened to me a number of times. I usually cruise along at 10-12 mph. I believe at higher speeds, you're more likely to be thrown (even 'launched') from the bike headfirst, and this is what causes the most serious accidents. I'm not sure what the actual 'danger speed' is (15 mph? 20??). I don't know why anyone ever discusses this, or does any research. Seems to me, this could be important to know. I also had a car stop suddenly in front of me. But it was on a congested street, so traffic (and me) was not going that fast. For some reason, I took my eye off the car in front of me for a second or two, and when I realized I was going to hit, I swerved, and ended up bruising my knuckles when my fingers hit the back of the car. Not fun, but I didn't crash. I had one slow speed crash when I had to swerve to avoid a car in a gas station convenience store parking lot, and ran right into the crack around the underground gas tanks. The tire got stuck, and even though I was only going 5-8 mph, the bike stopped completely but I kept going, and my body flew off, face first. I put my arms out and hit the ground. My left wrist absorbed some of the impact, and was sore. My right arm absorbed the rest of the impact, and sprained. I couldn't move my right arm properly for days. It was a skinny road bike tire that got stuck in the crack. I got rid of that bike, and ride a hybrid now. I'm careful, have lights, have a mirror, and look out for trouble. But no helmet.

There is no such thing as "danger speed." It's not the speed you're going, it's how fast the car that hits you is going, or even how far you fall from perched on your bike seat to hitting pavement. You can be the best bicyclist in the world, but an errant driver in a 4000 pound car is no match.

No, it's your traveling speed. Look at all of the stories published by the bike helmet people on their own website. Most of those people were going too fast when they hit an obstruction or ran off a mountain bike trail and had their accident. They experienced an 'endo', which is their cute term for flying off their bike head first. That's the danger right there. THOSE people who speed, or are reckless, NEED their helmets, because they're doing risky behaviors. THE REST OF US, who go at slower speeds, watch out/be careful, don't need helmets. Saying 'everyone' needs a helmet makes people think biking is dangerous, and they'll never get on a bike because of it. When I've skidded down wet pavement on a hill, or been 'doored', I never went down head first. Always, my body went down with the bike. Again, because of physics. If I had to wear protective equipment based on my accidents, I'd have armor on nearly every part of my body EXCEPT my head.You say 'hit by car', but that happens to people who run red lights, or ride down a sidewalk on the wrong side of the street. Again, dangerous behavior. One woman just got killed because she turned in front of a motorcycle. And she was wearing a helmet. Caution is worth more than any helmet.Could a 2000 pound death machine/car 'come out of nowhere' and hit/kill me, no matter how safe I am? Yes. But it can happen to people who are in cars, too. It's exceedingly rare.People who bike dangerously need a helmet. People who bike safely don't. We need to spread the message that biking can be safe, and instruct the public on safe biking behavior. The message that helmets send, that biking is unsafe, is incorrect and keeps people from riding bikes.

No matter what speed you are traveling, Skelter Weeks, a bicycle helmet will never create a worse outcome, and can only make your situation better. I've been in accidents ranging from 2 mph to 17 (?) where a bicycle helmet has helped. If it is reckless to bike down a bike lane obeying traffic laws at a normal rate of speed (15 mph), then a lot of cyclists are recklessly biking. If you toodle along at 8 mph, that's fine, but a helmet will still help if a car runs a light in to you. And even if your body goes down with your bike, your head may hit the pavement. If it's not a controlled fall, the side of your head may well hit the ground. That's what happened in the accident I described: my leg and arm took most of the brunt of the accident. My head sort of whiplashed in to the ground as I skidded down. But my helmet still took up some force. Cars coming out of nowhere is not exceedingly rare. And if it is so rare, maybe we should all drive without seat belts.

People who bike safely in environments with drivers who drive dangerously need helmets. Unless you are a Dutchman or a Dane with very good English, you live somewhere where that is the case.

Well since I have not been in a car accident since 2001, I guess I can drop my car insurance since insurance only pays off when you are in an accident....I saved my brain once by wearing a helmet and will continue to do so. That way I may be alive to attend funerals of those that don't....I made fun of helmets when I started riding as an adult, but the more I ride, the more sense they make.

I grew up cycling in Los Angeles pre-1970. This is a cycling background that will render any intelligent person a helmet wearer for life. US drivers descended to subhuman status in LA much earlier than in the rest of the country. No matter how much you wish you were in Copenhagen, you're not if you're in North America!

Traumatic Brain Injury is the most dangerous injury. I have been told in the childhood by my parents about it. Since then I take care of my head from getting hit or stroke of any kind. Now as I grew old, I wear helmet whenever I ride my bike. At the construction companies also, I recommend all the workers to wear safety helmets so that if anything falls on their head then helmets protect them.